Controllable pitch propeller



March 6, 1962 1.. H. BLOUNT 3,023,814

CONTROLLABLE PITCH PROPELLER Filed Feb. 24, 1960 5 Sheets-Sheet 1 INVENTOR.

LUTHER H. BLOUNT ATTORNEYS March 6, 1962 L. H. BLOUNT CONTROLLABLE PITCH PROPELLER 3 Sheets-Sheet 2 Filed Feb. 24, 1960 INVENTOR. LUTHER H. BLOUNT ATTORNEYS March 6, 1962 L. H. BLOUNT 3,023,814

CONTROLLABLE PITCH PROPELLER Filed. Feb. 24, 1960 s Sheets-Sheet 3 INVENTOR.

LUTHER H; BLOUNT ATTORNEYS United States Patent 3,023,814 CONTROLLABLE PITCH PROPELLER Luther H. Blount, 459 Water St., Warren, RJ. Filed Feb. 24, 1960, Ser. No. 10,672 8 Claims. (Cl. 170160.47)

This invention relates to a controllable pitch propeller such as is used for marine propulsion.

In the use of controllable pitch propellers, each blade of the propeller is rotated about a longitudinal aXis within itself to vary the pitch of the blades so that the amount of drive from the propeller may be governed and the direction of drive may also be governed as the blades may be switched from a position for driving ahead to a position for driving astern. Complex mechanisms have heretofore been utilized for turning the blades from one position to another.

One of the objects of this invention is to provide a simple form of mechanism for shifting the blades from one position to another in the propeller hub.

Another object of this invention is to accomplish a change of position of the propeller blades by deriving power from the rotation of the drive shaft.

A more specific object of the invention is to provide a nicely controlled manual application of the power of the drive shaft for shifting the blades from one position to another.

Another obiect of this invention is to provide a housing for the mechanical parts and to control the parts by a movement of the housing.

Another object of this invention is to increase the leverage on the propeller blade at the propeller hub as the blade swings toward increasing the driving angle of the blade where greater thrust is needed.

A further object of the invention is to provide for a blade in the propeller hub which may be removed from the hub under water and without removing the vessel from water.

A still further object of the invention is to provide a means for obtaining a mechanical force for assisting in removing the blade from the propeller hub.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fu ly described and particularly pointed out in the appended claims.

In the accompanying drawings;

FIGURE 1 is a sectional view somewhat diagrammatic illustrating the driving shaft, the driven shaft to the propeller hub and the control for the propeller blades interposed between the drive shaft and driven shaft:

FIGURE 2 is a sectional view on line 22 of FIG- URE 1;

FIGURE 3 is a perspective view of certain of the parts of the control mechanism;

FIGURE 4 is a sectional view through the propeller hub showing the arrangement of the studs of the blades in the hub.

In proceeding with this invention, I have interposed a unit for controlling the blades of the propeller between the drive shaft and the driven shaft all located within the vessel in which the device is operable. The unit is such that it may be connected to a mechanism for moving a part such as a propeller blade in one direction or the other in order to cause the blades to move about their axis in one direction of rotation or the other direction of rotation by utilizing the power of the driving shaft.

With reference to the drawings designates the drive shaft which is driven from some suitable motor unit designated generally 11 which has a shaft extending therefrom. A flange 12 is fixed on the drive shaft and on this flange 12 there is shown a pulley 13 having V 3,023,814 Patented Mar. 6, 1952 grooves 14 in its periphery for the accommodation of a plurality of V belts to provide assistance in driving the shaft 10 when desired. This pulley 13 is bolted to the flange 12 as at 15.

The driven shaft is designated 16, and although it may be of a considerable length, it is shown as broken in FIGURE 1 to shorten it in illustration with the propeller hub 17 mounted at its outer end. The shaft will extend from inside of the hull out through the hull through a suitable stuffing box and hearing so that the propeller hub will be outside of the vessel. The shaft 16 is shown as provided with a flange 18 to which the hub 17 is bolted as at 19.

The control unit designated generally 20 is shown as interposed between the drive shaft 10 and the driven shaft 16 and is bolted to both of these parts so that the thread and gear assembly of the control unit will rotate with and transmit the drive from the drive shaft 10 to the driven shaft 16. A cover holding brake surfaces is attached to vessel by a torque bar and does not rotate.

This control unit 20 comprises a cylindrical member 21 composed of two parts 22 and 28. In FIGURE 3, I have shown the part 22 in perspective which shows generally a solid cylindrical part having a flange 23 at one end and provided with a slot 24 at its inner end with a central bore 25 extending therethrough. The outer surface of the inner end of this cylindrical part is threaded with a righthand thread 26. The flange 23 is bolted to the driven member 10 by bolts 27. The other part 28 of this cylindrical member is similarly shaped being solid with a flange 29 at its outer end while it is provided with a slot 30 at its inner end the same as the slot 24 in the inner end of part 22. Part 28 has a central bore extending therethrough as at 31 and is provided with lefthand threads 32 extending from its inner end along its outer surface. These two parts 22 and 28 are placed in end to end contacts so that their slots 24 and 30 register and are bolted together by four bolts 33 extending from the outer surface of the flange 23 through holes extending axially of the members and are in threaded engagement with thread holes in the part 28 so as to in effect form a single cylindrical member having a central slot, an axial bore therethrough and two threaded portions, one righthand and one lefthand, extending in opposite directions from the center.

A slide member 35 of the shape shown in FIGURE 3 is located within the slot 24, 30 of this cylindrical member and is of a size so that it may be moved axially in the slot from one end of the slot'to the other. A rod 36 is fixed to this slide member 35 and extends axially from the slide through the part 28 of the cylindrical member on one side and through a corresponding registering bore 37 through the driven shaft 16. The rod 36 is reduced at 38 and the slide 35 has a bore to slide over this reduced end and engage a shoulder formed by this reduction. A sleeve 39 is then slid over the reduced end and has threaded engagement with the end of the portion 38 it being of a length to engage the slide 35 and provide a second shoulder. Thus, the slide is held between two shoulders. The rod 36 and the sleeve 39 both have bushings 85, sweated on to their surfaces to provide a sliding fit in the bores 31 and 25 of the cylindrical member parts.

A collar 40 has threaded engagement with the righthand threads 26 on the cylindrical member and a collar 41 has threaded engagement with the lefthand threads 32 on the cylindrical member. Both threads are of the same pitch so that uniform movement axially will be had by either collar upon the same relative rotation of the collar and the cylindrical member. Collar 40 is provided with a bevel gear face 42, while the collar 41 is provided with a bevel gear face 43. These bevel gears ing 46 is also mounted upon this stud on the reduced portion 47 thereof to engage the faces of the two collars 40 and .41 and this ball-bearing and pinion are held in position by the nut 48 and lock nut 49. Thus, if either one of the collars is caused to rotate relative to the cylindrical member, it will impart equal and opposite rotation to the other collar so that both collars will move axially along'the cylindrical member should either one be actuated.- Abrake face 50 on collar 40 and brake face 51 on collar 41 are secured to the outer face of each of these collars adjacent its outer periphery.

A casing 52 formed in two parts 53 and 54 each with flanges 55 and 56 is provided to house these collars and this gearing. The flanges are secured together by suitable fastenings 57. This casing is mounted on the cylindrical member through ball bearings 58 and 59, the casing being held against the rotary motion of the cylindrical member which turns with the drive shaft. Also in normal operation it will be apparent that the collars and slide-all rotate together with the cylindrical member while this casing is stationary. Helical springs 60 and portion of the propeller hub 17 so that should the nut 80 be backed off from the threaded portion 79, it will engage the wall 82 of this recess and by turning the nut so as to increase its pressure on the wall 82, the nut will force the tapered solid stud 77 outwardly so as torelease it from the tapered bore of the hollow stud 70 thus ejecting it from the hub. By this means a skindiver may readily disconnect a propeller blade 78 and insert another one under water by merely manipulating the nut 80 for this purpose.

A plurality of slots 85 (here shown as three) extend axially from the aft end of the mid section 17 in a compact arrangement at locations to intersect each bearing 17 for the blade studs 70 intermediate the ends of the bearing 17 and as shown are substantially midway of each of these bearings (see FIG. 4). Each'slot 85 terminates short of the opposite end of hub mid section 17*- (FIG. 1). The spider 75 is also slotted as at 86 throughout its axial extent as a continuation of the slots 85. The extents of these slots are suflicient to accommodate in each slot a separate arm 71 to embrace and be fixed to the blade stud 70. In this compact oriented 61 are interposed between the ball bearings which are fixed to the casing and the collars 40 and 41, this whole casing being so mounted on the cylindrical member that it may be'shifted axially thereof through the link 62 which is fixed by a clevis 63 to the casing and also fixed to the lever 64 which may be moved from its position shown in full lines to either of the center lines 65 or 66 as shown in FIGURE 1.

The inside of the casing is provided with a brake face 67 for engagement with the brake shoe 50 and brake face 68 for engagement with the brake shoe 51. Thus, if the lever 64 is moved so as to bring the surfaces 50, 67 into engagement, the collar 40 will be retarded with reference to the rotation of the cylindrical member 21 r and through its threaded connection thereto will be caused to move to the left and will cause an opposite rotation of the collar 41 which also will be caused to be moved to the left which through the slide 35 and the rod 36 will cause the rod to be moved to the left so as to rotate the blade clockwise in the hub as seen in FIG. 1. Should the lever 64 be moved in the opposite direction, the opposite direction of movement will be given to the rod to move the propeller blade counter clockwise. The action thus given to the rod will continue so long as the lever is held so that any braking force is applied. Some limits may be provided to prevent overrun. The propeller blades are locked in position by reason of the right and lefthand threads.

7 The propeller hub 17 comprises a one piece solid mid section 17 having a central axial bore 17 in which a correspondingly shaped spider 75 is located and which 1 is guided by the walls of the bore for sliding movement axially of the hub. The mid section 17 has a plurality .(here shown as three) of bearings 17 for the blade studs 70. These bearings have their axes in a plane at right angles to the hub axis midway of the axial extent of the mid section and spaced from the'hub axis. 'Each bearing opens outwardly into the outer surface 17 of the hub mid section 17 7 The blade studs 70 are here shown as each comprising a hollow stud 70 which rotates in the bearing 17 and which has a tapered bore 76 to receive the tapered solid stud 77 of the blade78. This solid stud 77 is keyed to the hollow stud 70 for purposes of blade alignment and for rotation therewith so as to function as a single part.

The stud 77 is drawn into position by means of threads ,79 on its end which are engaged by a nut 80. This threaded portion .79 of the solid stud and nut 80 are located in an externally accessible recess 81 in the solid arrangement each arm 71 extends inwardly radially of its blade stud axis in substantially a single plane. The arm will be of a thickness substantially the width of its slot to be guided by the walls of the slot in its swinging movement therein about the axis of its blade stud. The arm will be positioned in the slot prior to the positioning of the stud in its bearing and then the stud will be passed through the opening in the arm. A Dutch key will hold the arm 71 fixed against axial movement and against rotation relative to the hollow stud 70 and thus the two will move together. In this manner the stud has a bearing of substantial extent on either side of the arm 71. This arm 71 has its center in the same plane as the plane of'the blade and is provided with a center slot 72 in its inner end as seen in FIGURE 1 which receives a square block 73 mounted on a pin 74 which is carried by the spider '75. This pin 74 is in a hole 87 in the spider which hole extends inwardly from the outer surface of the spider across the slot 86 in which the block is located and into the'spider at 88 on the opposite side of the slot 86 so as to providea good support for the pin 74 at spaced locations with the working portion of the pin between those two supports 87, 88 for the pin. This pin 74 is held in place by being substantially the length of the hole 87, 88 with its end engaging bore 17 and as here shown the rod 36 so it cannot come out.

The spider is fixed to the rod 36 so that as the rod moves axially of the shaft, the spider is likewise moved and will rotate all of the blade studs 70 at the same time and uniformly, the leverage acting through each arm 71 being increased as the blade angle is progressively shifted to increase its driving pitch by the block sliding outwardly of each slot 72 in'the arm 71 to increase its leverage action. We thus have a plurality of slotted arms compactly arranged in a propeller hub and each operated simultaneously by radially disposed pins increasing the leverage applied to the arms as the pitch of the blades is increased;

' I claim:

l. A propeller comprising a hub having a plurality of stud receiving holes therein, slots in said hub extending inwardly from the outer surface of the hub and each intersecting one of said holes, blades each having a stud to enter one of said holes with a threaded portion on the end of the stud projecting into one of, said slots and adjacent the wall of the slot distant from the hole, a nut on said threaded portion of the stud of a thickness to engagesaid wall while still in threaded engagement with saidstud so as to force the stud away from said wall upon being rotated while in contact with said wall.

, 2. A propeller as in claim 1 wherein said holes and studs have corresponding tapers.

3. A controllable pitch propeller comprising a hub, at least three blades each having a stud rotatably mounted in said hub on an axis in a plane at right angles to the axis of the hub and spaced from said hub axis, an arm for each blade extending inwardly of the hub from the axis of said blade stud, each arm having a slot therein, a spider axially movable of said hub carrying pins supported at spaced locations with the intermediate portions entering said slots and movable along said slots to increase their leverage action on said arms as said spider is moved axially of said hub.

4. A controllable pitch propeller comprising a hub with a central bore, at least three blades each having a stud rotatably mounted in said hub on an axis in a plane at right angles to the axis of the hub and spaced from said hub axis, an arm for each blade extending inwardly of the hub from the axis of said blade stud, each arm having a slot therein, a spider axially movable of said hub and guided by the walls of said bore, pins carried by said spider in holes therein of substantially the length of the pin with one end of the pin engaging the wall of the bore to hold it in place, said pins being supported at spaced locations with the intermediate portions entering said slots and movable along said slots to increase their leverage action on said arms as said spider is moved axially of said hub.

5. A controllable pitch propeller comprising a hub, at least three blades each having a stud rotatably mounted in said hub on an axis in a plane at right angles to the axis of the hub and spaced from said hub axis, an arm for each blade extending inwardly of the hub from the axis of said blade stud at a location intermediate the axial extent of said stud, each arm having a slot therein, a spider coaxial of the hub axis axially movable of said hub and carrying pins supported at spaced locations with the intermediate portions entering said slots and movable along said slots to increase their leverage action on said arms as said spider is moved axially of said hub.

6. A controllable pitch propeller comprising a hub, at least three blades each having a stud rotatably mounted in said hub on an axis in a plane at right angles to the axis of the hub and spaced from said hub axis, an arm for each blade extending inwardly of the hub from the axis of said blade stud, each arm having a slot therein, a block slidable in said slot, a spider axially movable of said hub carrying pins supported at spaced locations with the intermediate portions entering said block and movable with the block along said slots to increase their leverage action on said arms as said spider is moved axially of said hub.

7. A controllable pitch propeller comprising a hub, at least three blades each having a stud rotatably mounted in said hub on an axis in a plane at right angles to the axis of the hub and spaced from said hub axis, said hub having slots therein each at right angles to and intersecting the axes of a stud and opening to one end of the hub, a separate arm in each slot connected to each blade stud and extending inwardly of the hub from the axis of said blade stud at a location intermediate the axial extent of said stud, each arm having a slot therein extending radially of the arm, a spider movable axially of said hub carrying portions entering said slots and movable along said slots to increase their leverage action on said arms as said spider is moved axially of said hub.

8. A propeller comprising a hub having a plurality of outwardly opening stud receiving bearings therein with the axis of each bearing in a plane at right angles to the axis of the hub and spaced from the axis of the hub, said hub having slots extending axially inwardly from the aft end of the hub, each intersecting one of said bearings intermediate the ends thereof, blades each having a stud rotatably mounted in one of said bearings on both sides of said slot, an arm in each slot coupled to each stud and means movable axially of the hub and engaging each arm for rotating the blades in unison in said bearings.

References Cited in the file of this patent UNITED STATES PATENTS 

